Question

The arithmetic mean of -4,0,4,8,12,.....,40 is

Answer 1

Answer:

No. of terms n=tn-t1/d.+1

40-4/4. +1

36/4+I=10

sum=10/ 2{2a+(10-1)d }

= 10/2{2x-4+(10-1) 4}

= 5{-8+36}

= 5x28= 140

mean=140/10=14